Nitric Acid → 2,5-Dimethyl-1H-imidazole-4-carbaldehyde
Reaction equation
[CH3:1][C:2]1[NH:3][C:4]([CH3:9])=[C:5]([CH2:7][OH:8])[N:6]=1.[N+]([O-])(O)=O.C(=O)([O-])[O-].[Na+].[Na+]>>[CH3:1][C:2]1[NH:3][C:4]([CH3:9])=[C:5]([CH:7]=[O:8])[N:6]=1Participants
4
Procedure
A 42.2 gm. portion of 2,5-dimethyl-4-imidazolemethanol and 44.8 ml. of concentrated nitric acid are mixed. When the initial reaction subsides, the solution is heated on a steam bath for 1 hour. The reaction mixture is neutralized with concentrated aqueous sodium carbonate, then concentrated under vacuum. After leaching the residue with 150 ml. of hot ethanol several times, the combined organic solution are concentrated under vacuum. Chromatographing the residual oil on silica gel gives a solid which is recrystallized from isopropanolethyl acetate to give the desired product, m.p. 164.5°-166° C.